A higher image quality is demanded in the digital camera. To obtain an image of high quality, many pixels of a solid state imaging device are set, and a longer reading time is required. Accordingly, a pixel shifting technique is proposed recently in order to obtain a higher picture quality by a smaller number of pixels.
Various techniques about power source circuit for an optical camera are disclosed. For example, a power source circuit for camera is disclosed in Japanese Laid-open Patent No. 5-165080, and in this power source circuit for camera incorporating an oscillating wave motor and a flash device, a first voltage to be applied to a piezoelectric element of the oscillating wave motor for operating the mechanism in the camera, and a second voltage for operating the flash device are changed over by an output voltage changeover circuit depending on each operation by composing a boosting circuit by using a pair of boosting transformers, a switching element, an oscillation control circuit, and an output voltage changeover circuit, and it is designed to drive an ultrasonic motor for film take-up, an ultrasonic motor for lens driving, and a stroboscope circuit.
The power source circuit for camera disclosed in Japanese Laid-open Patent No. 7-301843 comprises a stroboscope emission device for stroboscope emission, a capacitor for accumulating emission energy for emitting this stroboscope emission device, charging means for boosting the supply voltage of the battery, and charging the capacitor by the boosted voltage, an actuator provided in the camera, a drive circuit for driving the actuator, changeover means for supplying either the emission energy accumulated in the capacitor or the energy from the power source battery selectively to the actuator or the drive circuit, supply voltage detecting means for detecting the supply voltage, temperature measuring means for detecting the environmental temperature of the camera, and control means for controlling the changeover means by selecting either the capacitor or the supply voltage on the basis of the supply voltage detected by the supply voltage detecting means and the environmental temperature detected by the temperature measuring means, in which the capacitor for accumulating the stroboscope emission energy is used as the power source, and the driving source for the lens driving mechanism of camera and film feed mechanism is obtained.
However, in the power source circuit for camera disclosed in Japanese Laid-open Patent No. 5-165080, a large circuit scale is required because the output changeover function is needed in the boosting circuit. In the power source circuit for camera disclosed in Japanese Laid-open Patent No. 7-301843, only the technique of driving the lens driving mechanism of camera and the film feed mechanism is disclosed by using the capacitor for accumulating the stroboscope emission energy as the power source, and nothing is proposed about the power source technology of the piezoelectric element for displacing the imaging device.